Charge holder for explosive cutter

ABSTRACT

Charge holders and methods for making charge holders, the charge holders including a first portion formed of a first material, the first portion having a longitudinally discontinuous internal feature integrally formed therein and a second portion formed of a second material, the second portion extending from the first portion and defining a charge support channel. The longitudinally discontinuous internal feature is formed from at least one third material, wherein at least one the third material is different from the first material.

BACKGROUND

The subject matter disclosed herein generally relates to explosivecutters and, more particularly, to charge holders for linear shapedcharge explosive cutters.

Explosive cutters, such as linear shaped charge devices, typically aremounted in a charge holder to secure the explosive cutter to a structure(e.g., an aircraft canopy, a wall, a door, etc.). The charge holder maybe arranged or designed to mitigate the effects of back blast in orderto prevent explosive concussion and/or material to be ejected in adirection away from an intended direction (e.g., away from a cuttingdirection). Charge holders are typically formed from a single material,such as a closed cell foam, rubber, or metal structure.

SUMMARY

According to some embodiments, charge holders are provided. The chargeholders include a first portion formed of a first material, the firstportion having a longitudinally discontinuous internal featureintegrally formed therein and a second portion formed of a secondmaterial, the second portion extending from the first portion anddefining a charge support channel. The longitudinally discontinuousinternal feature is formed from at least one third material, wherein atleast one the third material is different from the first material.

In addition to one or more of the features described herein, or as analternative, further embodiments of the charge holders may include thatthe first and second portions are integrally formed.

In addition to one or more of the features described herein, or as analternative, further embodiments of the charge holders may include thatthe longitudinally discontinuous internal feature comprises a pluralityof fiber structures, void structures, or lattice structuresdiscontinuously distributed along a longitudinal axis of the firstportion.

In addition to one or more of the features described herein, or as analternative, further embodiments of the charge holders may include thatthe longitudinally discontinuous internal feature comprises acombination of at least two of fiber structures, void structures, andlattice structures discontinuously distributed along a longitudinal axisof the first portion.

In addition to one or more of the features described herein, or as analternative, further embodiments of the charge holders may include thatthe second portion includes a floor shaped to receive a charge andsidewalls, wherein the floor and sidewalls define the charge supportchannel.

In addition to one or more of the features described herein, or as analternative, further embodiments of the charge holders may include thatthe longitudinally discontinuous internal feature comprises a pluralityof subfeatures discontinuously distributed along a longitudinal axis ofthe first portion, wherein locations between the discontinuouslydistributed subfeatures of the first portion are solid.

In addition to one or more of the features described herein, or as analternative, further embodiments of the charge holders may include acharge located within the charge support channel.

In addition to one or more of the features described herein, or as analternative, further embodiments of the charge holders may include atleast one initiator attached to at least one of the first portion andthe second portion and operably connected to the charge to initiate anexplosion of the charge.

In addition to one or more of the features described herein, or as analternative, further embodiments of the charge holders may include oneor more external features formed on the first portion, wherein the oneor more external features are arranged to receive an attachmentmechanism to attach the charge holder to a structure to be cut.

In addition to one or more of the features described herein, or as analternative, further embodiments of the charge holders may include thatthe structure to be cut is a portion of an aircraft, a portion of alaunch vehicle, a portion of a door, or a portion of a wall.

In addition to one or more of the features described herein, or as analternative, further embodiments of the charge holders may include thatthe second portion is arranged to direct a blast of a charge out of thecharge support channel and away from the first portion.

In addition to one or more of the features described herein, or as analternative, further embodiments of the charge holders may include thatthe at least one third material is at least one of a liquid, a solid,and a gas.

In addition to one or more of the features described herein, or as analternative, further embodiments of the charge holders may include thatthe first material and the second material are the same material.

In addition to one or more of the features described herein, or as analternative, further embodiments of the charge holders may include thatthe longitudinally discontinuous internal feature comprises at least oneof fibers, granules, powder, fluids, gels, wires, lattice structures,fiber structures, granules of material, powder materials, cavities,voids, gaps, and void patterns.

According to some embodiments, methods for manufacturing charge holdersare provided. The methods include forming a first portion using a firstmaterial, integrally forming a longitudinally discontinuous internalfeature within the first portion, and forming a second portion using asecond material, the second portion formed to extend from the firstportion and define a charge support channel. The longitudinallydiscontinuous internal feature is formed from at least one thirdmaterial, wherein at least one the third material is different from thefirst material.

In addition to one or more of the features described herein, or as analternative, further embodiments of the methods may include that thefirst and second portions are integrally formed.

In addition to one or more of the features described herein, or as analternative, further embodiments of the methods may include that thelongitudinally discontinuous internal feature comprises a plurality offiber structures, void structures, and/or lattice structuresdiscontinuously distributed along a longitudinal axis of the firstportion.

In addition to one or more of the features described herein, or as analternative, further embodiments of the methods may include that thefirst portion, the second portion, and the longitudinally discontinuousinternal feature are additively manufactured as a unitary body.

In addition to one or more of the features described herein, or as analternative, further embodiments of the methods may include forming oneor more external features on the first portion, wherein the one or moreexternal features are arranged to receive an attachment mechanism toattach the charge holder to a structure to be cut.

In addition to one or more of the features described herein, or as analternative, further embodiments of the methods may include that thefirst portion and the at least one internal feature are formedsubstantially simultaneously.

The foregoing features and elements may be combined in variouscombinations without exclusivity, unless expressly indicated otherwise.These features and elements as well as the operation thereof will becomemore apparent in light of the following description and the accompanyingdrawings. It should be understood, however, that the followingdescription and drawings are intended to be illustrative and explanatoryin nature and non-limiting.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter is particularly pointed out and distinctly claimed atthe conclusion of the specification. The foregoing and other features,and advantages of the present disclosure are apparent from the followingdetailed description taken in conjunction with the accompanying drawingsin which:

FIG. 1 is a schematic illustration of an example structure having aseverable portion to be cut from the structure using an explosivecutting action;

FIG. 2 is a schematic illustration of a charge for generating anexplosion for cutting a target;

FIG. 3 is a schematic illustration of a charge holder in accordance withan embodiment of the present disclosure;

FIG. 4 is a schematic illustration of a charge holder in accordance withanother embodiment of the present disclosure;

FIG. 5 is a partial illustration of a charge holder in accordance withanother embodiment of the present disclosure;

FIG. 6 is a partial illustration of a charge holder in accordance withanother embodiment of the present disclosure;

FIG. 7 is a flow diagram of a method of forming a charge holder inaccordance with an embodiment of the present disclosure;

FIG. 8A is a schematic illustration of a charge holder in accordancewith an embodiment of the present disclosure;

FIG. 8B is a cross-sectional illustration of the charge holder as viewedalong the line B-B of FIG. 8A;

FIG. 8C is a cross-sectional illustration of the charge holder as viewedalong the line C-C of FIG. 8A; and

FIG. 8D is a cross-sectional illustration of the charge holder as viewedalong the line D-D of FIG. 8A.

DETAILED DESCRIPTION

As shown and described herein, various features of the disclosure willbe presented. Various embodiments may have the same or similar featuresand thus the same or similar features may be labeled with the samereference numeral, but preceded by a different first number indicatingthe figure to which the feature is shown. Although similar referencenumbers may be used in a generic sense, various embodiments will bedescribed and various features may include changes, alterations,modifications, etc. as will be appreciated by those of skill in the art,whether explicitly described or otherwise would be appreciated by thoseof skill in the art.

Referring to FIG. 1, a schematic illustration of an example structure100 having a severable portion 102. As shown in FIG. 1, the structure100 is a canopy 104 for installation on an aircraft. Although thepresent description is related to the canopy 104 as representative ofthe structure 100, those of skill in the art will appreciate thatvarious structures can be severable portions, whether initially intendedfor severability from the structure or severed intentionally but notoriginally designed for such separation. For example, severableportions, as used herein, can include other structures such as, but notlimited to, portions of walls or doors that are opened using embodimentsof the present disclosure, and are severable from the structure of thewall or door.

The severable portion 102 is separable from the structure 100 byactivation of an explosive cutter 106, as will be appreciated by thoseof skill in the art. The explosive cutter 106 is attached to thestructure 100 along a cutting line 108 that defines the periphery of theseverable portion 102 (when the severable portion 102 is attached to orpart of the structure 100). The explosive cutter 106 may be a linearcharge explosive that is housed within a charge holder, as describedherein. When the explosive cutter 106 is activated, the severableportion 102 is separated or ejected from the structure 100 and anopening 110 is formed in the structure 100, as shown.

Turning now to FIG. 2, a schematic illustration of a charge 212 forgenerating an explosion for cutting a target 214 is shown (e.g., asurface of a structure to be cut). As shown, the target 214 is a surfaceof a structure such as a portion of a wall, a door, an aircraft canopy,etc. (e.g., structure 100 shown in FIG. 1). The charge 212 is a linearcharge that is formed to provide an explosive cutting force in a cuttingdirection 216, i.e., toward the target 214 to be cut by the charge 212.The charge 212 includes an explosive material 218 that forms the charge212 or is supported or contained within a casing or liner, as will beappreciated by those of skill in the art.

The explosive material 218 has a “V-shaped” profile and can be formedwith a desired length. The charge 212 can include a tamp 220 or otherconfining structure, as will be appreciated by those of skill in theart, that surrounds the explosive material 218. The tamp 220 can beprovided to aid in directing the explosion of the explosive material218. A liner 222 can be provided on a side of the explosive material 218in the cutting direction 216. Upon detonation of the explosive material218, the shape of the charge 212 along with the tamp 220 focuses anexplosive high pressure wave toward the target 214. In some embodiments,as the explosive high pressure wave becomes incident to the tamp 220,the liner 222 of the charge 212 will collapse, thus creating a cuttingforce directed at the target 214. The detonation projects in the cuttingdirection to form a continuous, knife-like (planar) jet. The jet cutsany material in its path (e.g., the target 214), to a depth depending onthe size and materials used in the charge (e.g., the choice of explosivematerial 218). In some embodiments, a liner or other material or objectcan be positioned in the base of the “V-shape” which, upon detonation,becomes a projectile that performs the cutting action (e.g., isprojected in the cutting direction 216 to cut the target 214).

Explosive cutters, such as charge 212 shown in FIG. 2, can be mounted ina charge holder to secure the charge to the structure to be cut (e.g.,secured to the target 214). The charge holder may be arranged ordesigned to mitigate the effects of back blast in order to preventexplosive concussion and/or material (e.g., debris) to be ejected in adirection away from an intended direction (e.g., away from the cuttingdirection 216). Although designed to prevent or control back blast, suchmitigation may not be sufficient to protect objects that are near thecharge 212 at the time of detonation (e.g., the interior of an aircraft,with the canopy being cut to enable ejection of the pilot).

Embodiments described herein are directed to charge holders that provideimproved back blast mitigation. Various embodiments of the presentdisclosure are directed to additively manufactured charge holders suchthat the mechanical properties and mass distribution throughout thecharge holder are selectively controlled to optimize performance whilemitigating or preventing back blast. Embodiments described herein enablemanagement of debris (size and velocity of particles produced upondetonation) and resistance to induced mechanical environments. Bycontrolling various manufacturing and design characteristics (e.g.,shape, density of charge holder materials, location/thickness ofcontinuous fibers, mechanical properties, mass distribution, etc.) ofthe charge holder, the charge holder can be designed to specific orpredetermined back blast mitigation capabilities (e.g., debris size,speed, and direction of flight).

Embodiments of the present disclosure can take various shapes,geometries, and/or be formed from various different materials. Forexample, in some embodiments, the charge holders of the presentdisclosure can be formed from composite materials. For example, onenon-limiting example of a charge holder of the present disclosure is anylon material with graphite fibers embedded therein. Further, in someembodiments, internal features can be formed to provide additional backblast mitigation characteristics. For example, in a non-limitingexample, a honeycomb printed structure can be formed within an interiorof the charge holder. Additionally, in some embodiments, additionalsupport, structure, and/or material can be embedded within the chargeholder. For example, the addition of a para-aramid synthetic fiberstructure (e.g., Kevlar®) and/or strands printed within a graphitefiber/nylon material can provided additional back blast mitigation. Aswill be appreciated by those of skill in the art, the size, orientation,structure, shape, etc. of internal features and/or characteristicsand/or the amount/location of internal embedded materials can bedesigned to achieve desired back blast mitigation while also beingcatered to a specific application.

Turning to now to FIG. 3, a schematic illustration of a charge holder324 in accordance with an embodiment of the present disclosure is shown.The charge holder 324 supports a charge 312 therein. The charge 312 canbe a linear explosive charge to provide cutting action in a cuttingdirection 316. The charge holder 324 includes a first portion 326 and asecond portion 328. The first portion 326 is a base or structure of thecharge holder 324 that provides support and/or back blast mitigation.Further, the first portion 326 can provide a structure for engagementand/or attachment to a surface to be cut on a structure. The secondportion 328 defines a charge support channel 330 that holds or supportsthe charge 312 and can be geometrically shaped to correspond to a shapeand size of the charge 312 (i.e., at least a portion of the chargesupport channel 330 is complementary to the charge 312). The first andsecond portions 326, 328 can be formed as a single body and of a singlematerial. For example, the first and second portions 326, 328, in anexample embodiment, is formed from a composite material, including butnot limited to, nylon reinforced with carbon, fiberglass, aramid fibers,para-aramid fibers, para-aramid synthetic fibers, etc. In someembodiments, the first portion 326 may be formed from a first materialand the second portion 328 is formed from a second material that isdifferent from the first material. Such arrangements may be employed toachieve specific back-blast control and/or charge holding.

As shown, the charge holder 324 is formed with internal features. Forexample, as schematically shown in FIG. 3, the charge holder 324includes a fiber structure 332 and a void structure 334. The fiberstructure 332, as shown, is generally shaped in the geometry of thefirst and second portions 326, 328. Within the fiber structure 332, orsurrounded thereby, the void structure 334 is formed. The void structure334 can be a plurality of cavities 336 (e.g., holes, tubes, or othercavities) within the material of the charge holder 324. The location,number, geometry, size, etc. of the cavities 336 of the void structure334 can be selected to achieve a desired result (e.g., maximized backblast mitigation, reduced weight, etc.). In some embodiments, the voidstructure 334 can include cavities 336 that are filled with material(rather than being empty voids). In such embodiments, the materialwithin the cavities 336 can include fibers, granules, powder, fluids,gels, or other materials, compositions, and/or structures.

As described above, the first and second portions can be formed from thesame or different materials. The internal features can be positivestructures or negative structures within the first portion 326 and, insome embodiments, can extend into the second portion 328, asillustratively shown in FIG. 3. Positive structures within the firstportion 326 can include, without limitation, wires, lattice structures,fiber structures, granules or powder of material, etc. Negativestructures are shapes or structures that are defined by the material ofthe first portion and can include, without limitation, cavities, voids,gaps, a void pattern, etc. within the material of the first portion. Theinternal features, when positive, may be formed from one or more thirdmaterials that are different from the material(s) used to form the firstportion and/or the second portion. In some embodiments, the thirdmaterial may be a material that has different material properties fromthe material of the first portion (e.g., density, tensile/compressivestrength, brittleness, etc.). In accordance with some embodiments, theinternal features can be of unchanging shape or material throughout thefirst and second portions, or the shape or material can be different invarious sections of the first and second portions. The change ininternal features can be localized in nature or formed from one or morerepeated patterns.

In some embodiments, it may be advantageous to deposit or form granuleswithin the cavities 336. In some such embodiments, deposition orformation of granules can be achieved through selective laser sinteringand/or selective laser melting additive manufacturing processes. Theprocesses can form one or more layers of powder in the form of granules.In such formation, laser light is used to sinter or melt the powder inselected areas to form a desired net shape of the final product. Eachsubsequent layer of powder is laid down and heated with the laser tobuild the complete shape. The final shape may fully entrap powder if allmaterial surrounding it has be sintered/melted. Such trapped granules orpowder within the structure can provide additional benefits including,but not limited to, improvement in resistance to vibration.

In some embodiments, the third material may be the same as the secondmaterial. In accordance with embodiments of the present disclosure, thethird material can be a solid, a liquid, or a gas. That is, even whenthe internal features are voids or cavities, the voids or cavitiescomprise a third material (e.g., in the form of a gas). Thus, the term“third material” is not to be limiting to solids, but rather includesany phase state of one or more materials that form or fill the internalfeatures of the charge holders of the present disclosure.

The charge support channel 330 of the second portion 328 can be sizedand shaped to accommodate the charge 312 and also aid in directly and/orcontrolling an explosive jet that is generated by the charge 312 toperform a cutting action. For example, the second portion 328 may have apredetermined shape and size to offset the charge 312 from a target(e.g., a surface of a structure to be cut). As shown, the second portion328 includes a floor 338 and sidewalls 340. The floor 338 is shaped toreceive the charge 312, and in the present illustration is chevron orV-shaped to accommodate the like-shaped charge 312. The sidewalls 340extend away from the floor 338 (in a direction away from the firstportion 326) and the floor 338 and the sidewalls 340 define the chargesupport channel 330. As will be appreciated by those of skill in theart, the sidewalls 340 can provide an offset of the charge 312 from atarget (e.g., surface of a structure to be cut) by a predetermineddistance that allows the charge 312 to generate an explosive blast ofsufficient strength to cut the target.

Turning to FIG. 4, an alternative arrangement of a charge holder 424 inaccordance with the present disclosure is shown. Although substantiallysimilar to the charge holder 324 shown in FIG. 3, the internal featuresand features of the charge holder 424 shown in FIG. 4 are different. Inthis embodiment, the internal feature of the charge holder 424 includesa lattice structure 442. The lattice structure 442 can define a numberof lattice cavities 444 which can be empty/hollow or may be filled witha material that is different from the material of a first section of thecharge holder 424. The internal feature material within the latticecavities 444 can be the same material as used to form parts of thecharge holder 424 or may be different therefrom. The lattice structure442 may be formed form fibers or may be a solid structure. Variousgeometric shapes can be employed to form the lattice structure 442,including but not limited to, a honeycomb, triangular shapes, diamond,parallelograms, polygons, etc.

As shown and describe above, the charge holders are shown havinginternal features such as fiber structures 332, void structures 334,and/or lattice structures 442. Various combinations thereof can beemployed to achieve a desired result, such as improved back blastmitigation. As used herein, the various structures shown and describedabove may be referred to herein as “internal feature(s).”

In addition to being formed with internal features as shown anddescribed above, charge holders as described herein may be formed in anygeometric shape or size to accommodate installation to a structure to becut. For example, turning to FIGS. 5-6, example structures of chargeholders in accordance with embodiments of the present disclosure areshown.

FIG. 5 illustrates a charge holder 524 having a charge 512 installedtherein. As shown, the charge holder 524 includes a 90° turn, which canbe formed during an additive manufacturing process of the presentdisclosure. Further, as shown, the charge holder 524 is attached to aninitiator 546 (e.g., initiation manifold). The initiator 546 is arrangedto ignite the charge 512 within the charge holder 524 such that acutting action is performed against a target, in the shape of the chargeholder 524.

FIG. 6 illustrates a curved charge holder 624 that defines a cut-out 648that defines a portion of a target that will be removed after activationof a charge within the charge holder 624. Also shown in FIG. 6, thecharge holder 624 can include one more initiators 646 that may initiatean explosive cutting action of a charge within the charge holder 624.Further, the charge holder 624 can be formed with various externalfeatures 650. The external features 650 may be formed in the secondportion (e.g., second portion 326 shown in FIG. 3). In some embodiments,the external features 650 may be designed to enable attachment of thecharge holder 624 to a structure. For example, one or more attachmentmechanisms can be used to securely position and retain the charge holder(and charge) to a location on a structure such that a specific,predetermined cutting can be performed on the structure. Attachmentmechanisms can include, but are not limited to, brackets, bolts,fasteners, adhesives, clamps, etc.

Turning now to FIG. 7, a flow process 700 for manufacturing a chargeholder in accordance with an embodiment of the present disclosure isshown. The flow process 700 can be employed to manufacture chargeholders as shown and described herein. The manufacturing process, insome embodiments, employs additive manufacturing techniques and as suchvarious of the steps of flow process 700 can be performed simultaneouslyor substantially simultaneously. As such, in some embodiments, thevarious steps of the flow process 700 may be employed to form a unitarybody charge holder, wherein the first portion, the second portion, andthe internal features form an integrally formed unitary body.

At block 702, a first portion of a charge holder is formed. The firstportion may be formed with one or more external features at one or morelocations, with the external features designed for attachment and/orother purposes (e.g., attachment to a structure to be cut, connection toone or more initiators, etc.).

At block 704, one or more internal features are formed within the firstportion. The internal features can be positive structures or negativestructures. Positive structures within the first portion can includewires, lattice structures, fiber structures, granules of material, etc.Negative structures are shapes or structures that are defined by thematerial of the first portion and can include, without limitation,cavities, voids, gaps, a void pattern, etc. within the material of thefirst portion. The internal features, when positive, may be formed frommaterials that are different from the material used to form the firstportion and/or material having different material properties from thematerial of the first portion (e.g., density, tensile/compressivestrength, brittleness, etc.).

At block 706, a second portion is formed. The second portion is formedintegrally or continuously with the first portion. The second portion isformed to define a charge support channel. The charge support channel isformed geometrically and/or sized to receive a charge, such as a linearshaped charge. The second portion can be formed using the same materialas the first portion (a first material) or may be different from thefirst portion (a second material), with the internal features beinganother material (a third material). In some embodiments, two or more ofthe first, second, and third materials may be the same material.

The flow process 700 can employ various materials for forming the chargeholder and/or parts thereof. For example, the first portion and secondportion can be formed using respective first material(s) and secondmaterial(s) and the internal features are formed using a respectivethird material(s). In some embodiments, the first and second materialsare the same material. Further, in some embodiments, different internalfeatures are formed of different third materials. In one non-limitingexample, the first and second portions are composed of nylon filled withcarbon fibers and the internal features are composed of para-aramidsynthetic fibers. The materials may be selected to provide efficientcutting to be achieved by a charge within the charge holder while alsominimizing, mitigating, and/or eliminating back blast in a directionaway from the cutting direction.

As noted, the flow process 700 is an example manufacturing process forforming a charge holder in accordance with the present disclosure.Although shown in a flow-process (e.g., an order), those of skill in theart will appreciate that the various steps may be performedsimultaneously, substantially simultaneously, or in discrete, separatemanufacturing steps. In some embodiments, two of the steps may beperformed simultaneously or substantially simultaneously, and the thirdstep may be performed separately. Thus, there is no intended limitationon the flow process 700 to be imparted by the illustrative flow. In onenon-limiting example, “substantially simultaneous” means that two stepshappen concurrently, e.g., in a printing process where one material isprinted for the first portion and a second material is printed for thesecond portion.

Turning now to FIGS. 8A-8D, schematic illustrations of a charge holder824 having a charge support channel 830 are shown. The charge holder 824is similar to that shown and described above, and thus similar featuresmay not be described again for simplicity and brevity. FIG. 8A is aperspective illustration of the charge holder 824. FIG. 8B is across-sectional illustration of the charge holder 824 as viewed alongthe line B-B of FIG. 8A. FIG. 8C is a cross-sectional illustration ofthe charge holder 824 as viewed along the line C-C of FIG. 8A. FIG. 8Dis a cross-sectional illustration of the charge holder 824 as viewedalong the line D-D of FIG. 8A.

As shown in FIGS. 8B-8D, the charge holder 824 includes a longitudinallydiscontinuous internal feature 852. As shown in FIG. 8B, thelongitudinally discontinuous internal feature 852 includes a firstsubfeature 852 a and a second subfeature 852 b. In this embodiment thefirst subfeature 852 a and the second subfeature 852 b have differentstructural shapes/geometries. For example, as shown in FIGS. 8B and 8C,the first subfeature 852 a comprises a plurality of longitudinallyextending internal features (either positive or negative, as definedabove) arranged in a pattern. Further, as shown in FIGS. 8B and 8B, thesecond subfeature 852 b comprises a single longitudinally extendinginternal feature. The charge holder 824 is solid at positions betweenthe first subfeature 852 a and the second subfeature 852 b. Although theinternal subfeatures shown in FIGS. 8A-8D are longitudinal in extent,such arrangement is not limiting. For example, the subfeatures of thepresent disclosure can be points (e.g., spherical in shape, particulate)or may have transverse structures, combinations of transverse andlongitudinal, etc. as will be appreciated by those of skill in the art.

Although shown in FIGS. 8A-8D with the longitudinally discontinuousinternal feature 852 having different geometries and shapes at differentlocations, such arrangement is not to be limiting. For example, a chargeholder in accordance with an embodiment of the present disclosure canhave a longitudinally discontinuous internal feature that comprises aplurality of the same structure internal features, different structureinternal features, all positive internal structures, all negativeinternal structure, combinations of positive and negative internalstructures, etc. Further, although shown in FIGS. 8A-8D with thelongitudinally discontinuous internal feature 852 having one twosubfeatures 852 a, 852 b, charges holders of the present disclosure canhave any number of subfeatures forming a longitudinally discontinuousinternal feature, and thus the illustrations and accompanyingdescription are not to be limiting, but rather are provided forunderstanding and illustrative purposes.

The term “discontinuous” as provided here, as it relates to thesubfeatures, means that the subfeatures do not extend an entirelongitudinal length of the charge holder. That being said, in someembodiments, a combination of discontinuous subfeatures and continuousinternal features can be employed without departing from the scope ofthe present disclosure. For example, referring to FIG. 3, a chargeholder of the present disclosure could have continuous fiber structure332 extending longitudinally and continuously from one end of the chargeholder 324 to another end of the charge holder 324, but the voidstructure 334 can be arranged in groups of discontinuous subfeatures,with sections of the charge holder 324 being solid between thediscontinuous subfeatures. Similar continuous and discontinuousarrangements could be employed with the configuration of FIG. 4.

Advantageously, embodiments described herein provide charge holders thatleverage additive manufacturing technique to selectively controlmechanical properties and mass distribution throughout the charge holderto optimize performance. Example, performance variables includemanagement of debris (size and velocity of particles produced upondetonation) and resistance to induced mechanical environments. Byprinting a shape, the density of the material, location/thickness ofcontinuous fibers, mechanical properties and mass distribution of thecharge holder can be designed to specific debris mitigation requirements(debris size, speed and direction of flight).

The use of the terms “a”, “an”, “the”, and similar references in thecontext of description (especially in the context of the followingclaims) are to be construed to cover both the singular and the plural,unless otherwise indicated herein or specifically contradicted bycontext. The modifier “about” used in connection with a quantity isinclusive of the stated value and has the meaning dictated by thecontext (e.g., it includes the degree of error associated withmeasurement of the particular quantity). All ranges disclosed herein areinclusive of the endpoints, and the endpoints are independentlycombinable with each other.

While the present disclosure has been described in detail in connectionwith only a limited number of embodiments, it should be readilyunderstood that the present disclosure is not limited to such disclosedembodiments. Rather, the present disclosure can be modified toincorporate any number of variations, alterations, substitutions,combinations, sub-combinations, or equivalent arrangements notheretofore described, but which are commensurate with the scope of thepresent disclosure. Additionally, while various embodiments of thepresent disclosure have been described, it is to be understood thataspects of the present disclosure may include only some of the describedembodiments.

Accordingly, the present disclosure is not to be seen as limited by theforegoing description, but is only limited by the scope of the appendedclaims.

1. A charge holder comprising: a first portion formed of a firstmaterial, the first portion having a longitudinally discontinuousinternal feature integrally formed therein; and a second portion formedof a second material, the second portion extending from the firstportion and defining a charge support channel, wherein thelongitudinally discontinuous internal feature is formed from at leastone third material, wherein at least one the third material is differentfrom the first material.
 2. The charge holder of claim 1, wherein thefirst and second portions are integrally formed.
 3. The charge holder ofclaim 1, wherein the longitudinally discontinuous internal featurecomprises at least one of a plurality of fiber structures, voidstructures, or lattice structures discontinuously distributed along alongitudinal axis of the first portion.
 4. The charge holder of claim 1,wherein the longitudinally discontinuous internal feature comprises acombination of at least two of fiber structures, void structures, andlattice structures discontinuously distributed along a longitudinal axisof the first portion.
 5. The charge holder of claim 1, wherein thesecond portion includes a floor shaped to receive a charge andsidewalls, wherein the floor and sidewalls define the charge supportchannel.
 6. The charge holder of claim 1, wherein the longitudinallydiscontinuous internal feature comprises a plurality of subfeaturesdiscontinuously distributed along a longitudinal axis of the firstportion, wherein locations between the discontinuously distributedsubfeatures of the first portion are solid.
 7. The charge holder ofclaim 1, further comprising a charge located within the charge supportchannel.
 8. The charge holder of claim 7, further comprising at leastone initiator attached to at least one of the first portion and thesecond portion and operably connected to the charge to initiate anexplosion of the charge.
 9. (canceled)
 10. The charge holder of claim 1,further comprising one or more external features formed on the firstportion, wherein the one or more external features are arranged toreceive an attachment mechanism to attach the charge holder to astructure to be cut.
 11. The charge holder of claim 10, wherein thestructure to be cut is a portion of an aircraft, a portion of a launchvehicle, a portion of a door, or a portion of a wall.
 12. The chargeholder of claim 1, wherein the second portion is arranged to direct ablast of a charge out of the charge support channel and away from thefirst portion.
 13. The charge holder of claim 1, wherein the at leastone third material is at least one of a liquid, a solid, and a gas. 14.The charge holder of claim 1, wherein the first material and the secondmaterial are the same material.
 15. The charge holder of claim 1,wherein the longitudinally discontinuous internal feature comprises atleast one of fibers, granules, powder, fluids, gels, wires, latticestructures, fiber structures, granules of material, powder materials,cavities, voids, gaps, and void patterns.
 16. A method for manufacturinga charge holder comprising: forming a first portion using a firstmaterial; integrally forming a longitudinally discontinuous internalfeature within the first portion; and forming a second portion using asecond material, the second portion formed to extend from the firstportion and define a charge support channel, wherein the longitudinallydiscontinuous internal feature is formed from at least one thirdmaterial, wherein at least one the third material is different from thefirst material.
 17. The method of claim 16, wherein the first and secondportions are integrally formed.
 18. The method of claim 16, wherein thelongitudinally discontinuous internal feature comprises a plurality offiber structures, void structures, and/or lattice structuresdiscontinuously distributed along a longitudinal axis of the firstportion.
 19. The method of claim 16, wherein the first portion, thesecond portion, and the longitudinally discontinuous internal featureare additively manufactured as a unitary body.
 20. The method of claim16, further comprising forming one or more external features on thefirst portion, wherein the one or more external features are arranged toreceive an attachment mechanism to attach the charge holder to astructure to be cut.